(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*

This guide provides a more detailed description of the syntax that is supported along with examples.

This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.

Concept Search - What can I type?

For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.

Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.

Publishing Venue

Related People

Abstract

In telecommunication equipment, we are often faced with the following problem: How to command a lot of independent Light Emitting Diodes (LEDs) with a minimum of Inputs/Outputs (I/Os) pins. The classical method is as follows (Fig. 1): (Image Omitted)

Country

United States

Language

English (United States)

This text was extracted from a PDF file.

This is the abbreviated version, containing approximately
100% of the total text.

Page 1 of 1

Command of Several Light Emitting Diodes with few Inputs/Outputs

In telecommunication equipment, we are often faced with the
following problem: How to command a lot of independent Light Emitting
Diodes (LEDs) with a minimum of Inputs/Outputs (I/Os) pins. The
classical method is as follows (Fig. 1):

(Image Omitted)

A register is written with a word of a length corresponding to
the number of LEDs to command and a control lead is used to load the
register. It is easily noticed that if the number of LEDs is growing
up, the needed I/Os of the chip are growing proportionally. If the
chip is a microprocessor or a microcontroller, we can use their data
bus plus a decode, so this solution is correct, but if the chip is a
gate array, an FPGA or an EPLD, each I/O is usable, and it is not
reasonable to use an I/O per LED to be driven. Another method can be
employed: The command information, issued from the chip, can be
serialized into the chip and then sent out to the shift register
(Fig. 2).

The output of each latch of the shift register can drive each
LED. This method gives the possibility to drive a large amount of
LEDs with only two I/Os. The update of the status of the LEDs can be
performed at any time without any perception of blinking if the clock
is fast enough (>1KHZ).

It is to be noticed that the clock is not a free running clock
but a burst sent by the chip. The number of clock beats is equal to
the number of LEDs to be commanded (Fig. 3).